The brains behind the brain

Blair Worden reviews Soul Made Flesh by Carl Zimmer

In what conditions does science advance? Scientists will tell you that its progress depends on the institutional security, and on the ample funding, of specialised research. Yet 17th-century England tells a different story. The scientific revolution throve on institutional anarchy, financial hardship, and the versatility of thinkers to whom boundaries of specialisation were unimaginable.

Its crucible was the Oxford of the civil wars. Before the quarrel of king and parliament, Oxford and Cambridge waxed stable and prosperous, thanks to the enlargement of their role during the Renaissance and Reformation. In the Middle Ages they had trained the clergy. Now they also educated the lay ruling class, which had taken over the clergy's political and administrative duties. Endowment expanded, student numbers rose, new chairs were founded.

Yet in that flourishing pre-war era, scientific inquiry made little headway in Oxford (and still less in Cambridge). The ancient orthodoxies of Aristotle and Galen saw off the new spirit of experiment and observation. The change came after Oxford had become Charles I's military headquarters, when student enrolment and the teaching system collapsed. The king's defeat, and the subsequent Puritan purge of the university, further depleted morale and resources.

Out of that chaos there grew the Oxford Experimental Philosophy Club, from which, at the Restoration in 1660, the Royal Society would emerge. The learned diarist John Evelyn, visiting Oxford in 1654, met the leading scientists, heard their disputations, visited the Anatomy School and the Physic Garden, and concluded that this "is doubtless the leading university now in the whole world".

Historians sometimes attribute the scientific revolution to the ideological energy of Puritanism, but there were more royalists than Puritans among the Oxford scientists. Christopher Wren (whom posterity knows as an architect but who, in that pre-specialist age, was first famed as an astronomer and as the man who could remove the spleen from a dog) came of a royalist family despoiled by the civil war. So did the pioneering chemist Robert Hooke. And so did the central figure of Carl Zimmer's remarkable book, Thomas Willis, who enlisted in Charles's army. It was in Willis's house in Merton Street that the conquered royalists gathered for forbidden Anglican services under the noses of the Puritan authorities.

Today a scientist as gifted as Willis would tread a well-worn path of promotion and preferment. Seventeenth-century routes to recognition were less conventional. He learned medicine, and financed his studies, by working for a don's wife who dispensed homely remedies to patients unable to afford a physician. He joined the ranks of the "piss-prophets" who competed for medical business on market days in the towns around Oxford, choosing cures on the evidence of urine brought by friends of the bedridden.

In time Willis would become a rich and respectable doctor, but it was his performances in the laboratory and lecture-hall that earned his lasting fame. With them the modern understanding of the brain, and of its command of the nervous system, began.

Previous medicine, ancient and modern, had generally disparaged the brain, instead locating the seat of thought and emotion in the heart or the soul. How, after all, could God have placed man's controlling faculties in the brain, which, to an anatomist lacking modern methods of preservation, quickly looks and feels like custard? The rise in the brain's status which Willis effected is revealed by the drawings, attractively reproduced in Zimmer's pages, with which Wren illustrated his findings. They portray the brain as a delicate, complex organ with the beauty of an orchid.

Scientific discovery is rarely the sudden victory of truth over error or the abrupt abandonment of old assumptions for new. The novel findings of Willis and his friends jostled in their minds with ancient ideas of alchemy and of the operation of divine providence. Only in the next century, when what Willis had traditionally thought of as animal spirits were gradually recognised as impulses of electricity, could the study of the brain be separated from the presuppositions about man's relationship to God and the universe that had obscured it.

Soul Made Flesh is a tour de force, eloquently and excitingly written, powerfully re-creating the atmosphere and personalities of the time, and making the science agreeably intelligible to the non-scientist. Exacting readers will sometimes wish that Zimmer had identified his sources more fully and drawn a firmer line between fact and speculation. Squeamish ones may blanch at his unsparing accounts of the sawing and slicing of the skulls and brains of executed criminals, who provided the anatomists with their standard source of human cadavers.

Be brave, for few books of recent times have brought the skills of science and history so instructively and enjoyably together.

Blair Worden's books include 'Roundhead Reputations: The English Civil Wars and the Passions of Posterity' (Penguin).